custom_bsp_helloworld

About

The custom BSP helloworld is an example project of how to use your own BSP with Greenwaves SDK. It provides:

• A Custom BSP folder including fictional board and driver definition.
• A basic compile-only helloworld application.

Please, check out GAP SDK documentation to learn more about how to use the custom BSP feature.

Custom BSP composition

Kconfig

This custom BSP provide a new board unknown to GAP SDK, it is defined in the following file:

custom_bsp/kconfig/board.kconfig

config BOARD_CUSTOMER_BOARD
    bool "Customer Board"
    select CHIP_GAP9_V2_WLCSP
    select HAS_APS256XXN_HARDWARE
    select HAS_MX25U51245G_HARDWARE
    select HAS_TLV320_HARDWARE
    select HAS_MCP9808_HARDWARE

This fictional board assume it embbeds a GAP9 processor with four hardware peripherals :

1. A RAM device : APS256XXN
2. A Flash device : MX25U51245G
3. An ADC device : TLV320
4. A temperature sensor device : MCP9808

Some of these drivers are known from the GAP SDK. The last one is a new one provided by the custom BSP in:

custom_bsp/kconfig/drivers.kconfig

config HAS_MCP9808_HARDWARE
    bool 
    help
        dummy temperature driver

menu "Custom drivers"
    config DRIVER_MCP9808
        bool "MCP9808"
        depends on HAS_MCP9808_HARDWARE
        select DRIVER_I2C
endmenu

CMake automatically manages the addition of these menus to those of the GAP SDK, simply by setting the cmake variable GAP_CUSTOM_BSP beforehand in your application CMakeLists.txt file (already done in this project).

Devicetree

This custom BSP also include a devicetree definition for the board defined above. This definition is available here:

custom_bsp/devicetree/customer_board.dts

/dts-v1/;
/plugin/;

/{
    customer1
    {
        compatible   = "gwt, gap9";
        target-path  = "/";
        __overlay__
        {
            mcp9808: mcp9808
            {
                status = "okay";
                sys
                {
                    device_name   = "mcp9808";
                    driver_name   = "mcp9808";
                    device_type   = "temperature";
                    device_board  = "customer_board";
                    device_driver = "bsp/drivers/mcp9808.h";
                };
                conf 
                {
                    i2c_itf   = <1>;
                    bsp_open  = "NULL";
                    bsp_close = "NULL";
                    bsp_conf  = "NULL";
                };
                pads
                {
                    i2c_sda = "GAP9_PADMUX(42,0,-1)";
                    i2c_scl = "GAP9_PADMUX(43,0,-1)";
                };
            };
        };
    };
};

This devicetree tells that the MCP9808 device is connected to the GAP9's I2C1 interface via pads 42 and 43.

BSP

The custom BSP also provide a set of .c/.h files where to implement board related function. These files are available here :

custom_bsp/bsp/boards/bsp_customer_board.c.h

Concerning peripherals, their driver can be stored here :

custom_bsp/bsp/drivers

How to run this project

1. Clone the last available verison of the GAP SDK
2. Follow the GAP SDK installation process until its compilation
3. Set the environnement variable GAP_CUSTOM_BSP to the path of this project's custom BSP.
4. Go into this project's helloworld application.

cd helloworld

5. Configure CMake for this application.

cmake -B build

6. Build and run the application

cmake --build build -t run